Asynchronous STW resonators with the high quality factor and reduced sizes

Abstract

Surface transverse waves (STW) on quartz have the high propagation velocity, which is higher by 60% than velocity of the Rayleigh surface acoustic waves (SAW), high temperature stability comparable with temperature stability of SAW on quartz. Those advantages allow successfully use STW in the high frequency resonators. However, a large number of the electrodes 400 in the reflectors is required to ensure the high quality factor of the resonators. This leads to increase the resonators sizes, especially on the frequencies < 1000 MHz. The 500-1000 MHz STW resonators with high quality factor on 36°YX90° cut quartz and reduced size were presented. Use of the asynchronous topology, constructional, topological and technological optimization with a computer simulation on the base of a equivalent circuit model allowed obtain in the frequency range of 500-1000 MHz the high quality factor of 8600-9500, reduced sizes of the topology in comparison with the known prototypes and place the resonators in the 3×3×1.2 mm and 5×5×1.8 mm SMD packages. The developed STW resonators with high quality factor and reduced sizes will be widely used in the miniature low noise oscillators.